Lesson 4/Learning Event 1
From the pickup screen, the oil is usually routed through a pipe or a tube to the inlet side of the oil pump.
There are several types of oil pumps in use in modern automotive engines. All of them can be classified as
positive displacement pumps, because they are pumping oil anytime the engine is running. Depending on the
method used to pump the oil, the pumps are called gear, vane, rotor, or plunger types. The gear and rotor
types are the most commonly used in automotive engines. In practically all cases, the pumps are driven by a
gear on the camshaft. In the case of gasoline engines, this gear is usually the same one that drives the ignition
FIGURE 57. GEAR-TYPE PUMP.
This is a top view of a gear-type pump. The upper gear is the driving gear. The gears revolve in the directions
indicated by the arrows.
On the inlet side of the pump, the teeth on the driving and driven gears are moving away from each other. Oil
is picked up at the inlet and is carried between the gear teeth and the housing to the outlet side of the oil